Heat pad



FIG. 1 is a perspective view of an embodiment of a heat pad showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a front elevation view thereof showing a first mode in use; and,

FIG. 5 is a front elevation view thereof showing a second mode in use.

The broken line environmental showing is for illustrative purposes only and does not form part of the claimed design. 

CLAIM The ornamental design for a heat pad, as shown and described. 